[FFmpeg-devel] [PATCH 2/2] avformat/mpegts: Skip over broken 0x80 headers

Carl Eugen Hoyos cehoyos at ag.or.at
Fri Apr 29 13:52:32 CEST 2016

Hi Ronald!

> So, since you're stating this as fact, I would like to point out that this
> was never formally agreed by any group of FFmpeg developers, and this is
> certainly not the official position. 

Your message surprises me: The mpegts demuxer (before this discussed patch) 
accepts all kind of broken streams. Most of the non-trivial (and some of the 
more trivial) decoders we have accept clearly invalid input provided by users.
I remember that in the past, this was one of the main selling arguments in 
favour of FFmpeg.
I was under the impression that the only reason that demuxers and decoders 
are written like that is that we all want FFmpeg to support invalid streams 
as long as this doesn't affect valid streams. It also seems difficult to 
imagine that users typically wouldn't want FFmpeg to behave the way it does.
Are you now arguing writing decoders and demuxers like this was a mistake? 
That libavformat and libavcodec should only accept valid streams that conform 
to a specification?

Am I correct that your argument also applies to the adpcm_ms stream from the 
Baby Monitor? That user requests for decoding broken streams from whatever 
devices should be ignored from now on?

I just don't understand the whole point of this argumentation, what is it?

Carl Eugen

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